Autism is a developmental disorder characterized by severe impairments in social interaction and communication and by ritualistic - repetitive behaviors. Although the causes of autism are not known, evidence suggests that one area of brain abnormality in autism is the hippocampus and associated temporal lobe. To better understand the functional implications associated with temporal lobe abnormalities in autism the proposed study will recruit 30 persons with autism and 30 matched controls for trace classical eyeblink conditioning, a task that has been shown in human and animal studies to require an intact hippocampus. It is hypothesized that persons with autism will display impaired trace conditioning compared to controls and that the severity of impairment will correspond to impairment in cognitive and behavioral functioning. Findings from this study have implications for the pathogenesis and treatment of autism. In addition to enhancing the understanding of autism, this proposed B/START application will assist the principal investigator's transition to an independent research career studying the neurobiology of developmental disorders. The P.I. is currently on a leave of absence from a faculty position at the University of Louisville to obtain postdoctoral training at the University of Iowa Mental Health Clinical Research Center. During the fellowship the P.I. has gained expertise in brain imaging and the neural basis of psychiatric disorders. This B/START will aid the return of the P.I. to a faculty position at the University of Louisville (beginning September 1, 1999) and allow for funding to help establish a neuropsychological laboratory for the study of developmental disorders.